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Hands On Mineral Identification helps you to identify over 14,500 minerals! By M. Darby Dyar, Ph.D. See our DVD collection.
This picture is an example of early autrophs.
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Image courtesy of Corel Photography

Early Life

Over a very long time, gradual changes in the earliest cells gave rise to new life forms. These new cells were very different from earlier cells because they were able to get their energy from a different source -- the Sun.

Organisms that are able to make their own food by using the energy of the Sun are called autotrophs. Photosynthesis is the name of the process by which these autotrophs eat.

Because the autotrophic bacteria were able to feed themselves by using the energy of the Sun, they were no longer dependent on the same limited food supply as the earliest life and were able to grow and multiply. Over millions of years of evolution, these sun loving bacteria eventually led to modern day plants.

The appearance of organisms capable of photosynthesis was very significant -- if it weren't for the photosynthetic activity of these early bacteria, Earth's air would still be without oxygen and animals which need oxygen, including humans, could never have even begun!

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Traveling Nitrogen is a fun group game appropriate for the classroom. Players follow nitrogen atoms through living and nonliving parts of the nitrogen cycle. For grades 5-9.

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Traveling Nitrogen Classroom Activity Kit

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Photosynthesis

There are many different kinds of plants. Some have big leaves. Some have small leaves. Some even have flowers. All plants make their own food. When sunlight hits the leaves of a plant, photosynthesis...more

The First Living Cells

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Kingdom Plantae

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The Archean

The Archean is the name of the age which began with the forming Earth. This period of Earth's history lasted a long time, 2.8 billion years! That is more than half the expected age of the Earth! And no...more

Iron Ore Deposits

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Extreme Environments

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Extremophiles

It is easy for living creatures to survive and grow in some places. Other places make it tough for life to get by. Scientists call places that are hard on life "extreme environments". There is a special...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF